HOME PLANTS AND THEIR WAYS. 19 



dril, and root-climbing — which are usually characteristic of 

 different classes of climbers, combined in a single species. 



8. The tendrils of the Virginia creeper may here be 

 worth noticing. This plant can climb up a flat wall, and 

 is not adapted to seize sticks or twigs ; its tendrils do occa- 

 sionally curl round a stick, but they often let go again. 

 They, like bignonia tendrils, are sensitive to the light, and 

 grow away from it, and thus easily find out where the wall 

 lies up which they have to climb. A tendril which has 

 come against the wall is often seen to rise and come down 

 afresh, as if not satisfied with its first position. In a few 

 days after a tendril has touched a wall the tip swells up, 

 becomes red, and forms one of the little feet or sticky cush- 

 ions by which the tendrils adhere. The adherence is caused 

 by a resinous cement secreted by the cushions, and which 

 forms a strong bond of union between the wall and the ten- 

 dril. After the tendril has become attached it becomes 

 woody, and is in this state remarkably durable, and may 

 remain firmly attached and quite strong for as many as 

 fifteen years. 



9. Besides this sense of touch, by which a bignonia ten- 

 dril distinguishes between the objects which it touches, 

 there are other instances of much more perfect and incom- 

 prehensible sensibility. Thus, some tendrils, which are so 

 sensitive that they curl up when a weight of one thirtieth 

 or even one fiftieth of a grain is placed on them, do not 

 take the least notice of a shower of rain whose falling drops 

 must cause a much greater shock to the tendrils. 



10. Again, some tendrils seem to have the power of dis- 

 tinguishing between objects which they wish to seize and 

 their brother tendrils which they do not wish to catch. A 

 tendril maybe drawn repeatedly over another without caus- 

 ing the latter to contract. 



11. The tendrils of another excellent climber (Cobcea 

 %candens) possess some curious properties. The tendrils are 



